Multi-layer coating with diffusion barrier layer and erosion resistant layer

ABSTRACT

A multi-layer coating for a surface of an article comprises a diffusion barrier layer and an erosion resistant layer. The diffusion barrier layer may be a nitride film including but not limited to TiN x , TaN x , Zr 3 N 4 , and TiZr x N y . The erosion resistant layer may be a rare oxide film comprising YZr x O y . The diffusion barrier layer and the erosion resistant layer may be deposited on the article&#39;s surface using a thin film deposition technique including but not limited to, ALD, PVD, and CVD.

RELATED APPLICATIONS

This patent application is a continuation of U.S. patent applicationSer. No. 15/646,602, filed Jul. 11, 2017, which claims the benefit under35 U.S.C. § 119(e) of U.S. Provisional Application No. 62/362,936, filedJul. 15, 2016, both of which are incorporated herein in their entirety.

TECHNICAL FIELD

Embodiments of the present disclosure relate to multi-layer coatingsacting as a diffusion barrier and as an erosion resistant coating, amethod for forming a multi-layer coating, and a process chambercomponent coated with a multi-layer coating.

BACKGROUND

Various manufacturing processes expose semiconductor process chambercomponents to high temperatures, high energy plasma, a mixture ofcorrosive gases, high stress, and combinations thereof. These extremeconditions may erode the chamber components, corrode the chambercomponents, lead to diffusion of chamber components' materials to thesubstrates, and increase the chamber components' susceptibility todefects. It is desirable to reduce these defects and improve thecomponents' erosion, corrosion, and diffusion resistance in such extremeenvironments. Coating semiconductor process chamber components withprotective coatings is an effective way to reduce defects and extendtheir durability.

SUMMARY

Some embodiments of the present invention cover a multi-layer coating.The multi-layer coating may comprise a diffusion barrier layer selectedfrom a group consisting of TiN_(x), TaN_(x), Zr₃N₄, and TiZr_(x)N_(y).The multi-layer coating may further comprise an erosion resistant layerselected from a group consisting of YF₃, Y₂O₃, Er₂O₃, Al₂O₃, ZrO₂,ErAl_(x)O_(y), YO_(x)F_(y), YAl_(x)O_(y), YZr_(x)O_(y) andYZr_(x)Al_(y)O_(z). The erosion resistant layer may cover the diffusionbarrier layer.

In some embodiments, disclosed herein is a method for forming amulti-layer coating. The method includes depositing a diffusion barrierlayer onto a surface of an article. The diffusion barrier layer may bedeposited using a first deposition process selected from a groupconsisting of atomic layer deposition, physical vapor deposition, andchemical vapor deposition. The diffusion barrier layer may be selectedfrom a group consisting of TiN_(x), TaN_(x), Zr₃N₄, and TiZr_(x)N_(y).The method further includes depositing an erosion resistant layer ontothe diffusion barrier layer. The erosion resistant layer may bedeposited using a second deposition process selected from the groupconsisting of atomic layer deposition, physical vapor deposition, andchemical vapor deposition. The erosion resistant layer may be selectedfrom a group consisting of YF₃, Y₂O₃, Er₂O₃, Al₂O₃, ZrO₂, ErAl_(x)O_(y),YO_(x)F_(y), YAl_(x)O_(y), YZr_(x)O_(y) and YZr_(x)Al_(y)O_(z).

In some embodiments, the present invention covers a coated processchamber component. The coated process chamber component may comprise aprocess chamber component having a surface and a multi-layer coatingcoated on the surface. In certain embodiments, the multi-layer coatingmay comprise a diffusion barrier layer selected from a group consistingof TiN_(x), TaN_(x), Zr₃N₄, and TiZr_(x)N_(y). In certain embodiments,the multi-layer coating may further comprise an erosion resistant layerselected from a group consisting of YF₃, Y₂O₃, Er₂O₃, Al₂O₃, ZrO₂,ErAl_(x)O_(y), YO_(x)F_(y), YAl_(x)O_(y), YZr_(x)O_(y) andYZr_(x)Al_(y)O_(z). The erosion resistant layer may cover the diffusionbarrier layer.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure is illustrated by way of example, and not by wayof limitation, in the figures of the accompanying drawings in which likereferences indicate similar elements. It should be noted that differentreferences to “an” or “one” embodiment in this disclosure are notnecessarily to the same embodiment, and such references mean at leastone.

FIG. 1 depicts a sectional view of one embodiment of a processingchamber.

FIG. 2 depicts a deposition mechanism applicable to a variety of AtomicLayer Deposition (ALD) techniques, in accordance with embodiments of thepresent invention.

FIG. 3 depicts a deposition mechanism applicable to a variety ofChemical Vapor Deposition (CVD) techniques, in accordance withembodiments of the present invention.

FIG. 4 depicts a deposition mechanism applicable to a variety ofPhysical Vapor Deposition (PVD) techniques, in accordance withembodiments of the present invention.

FIG. 5 illustrates a method for forming a multi-layer coating on anarticle according to an embodiment.

FIG. 6A illustrates a coated chamber component having a diffusionbarrier layer with intact component layers and an erosion resistantlayer with intact component layers, in accordance with embodiments ofthe present invention.

FIG. 6B illustrates a coated chamber component having a diffusionbarrier layer with intact component layers and an interdiffused erosionresistant layer, in accordance with embodiments of the presentinvention.

FIG. 6C illustrates a coated chamber component having an interdiffuseddiffusion barrier layer and an erosion resistant layer with intactcomponent layers, in accordance with embodiments of the presentinvention.

FIG. 6D illustrates a coated chamber component having an interdiffuseddiffusion barrier layer and an interdiffused erosion resistant layer, inaccordance with embodiments of the present invention.

DETAILED DESCRIPTION OF EMBODIMENTS

Embodiments are described herein with reference to a multi-layer coatingthat includes a nitride layer acting as a diffusion barrier layer and arare earth oxide or fluoride layer acting as a corrosion and/or erosionresistant layer. The layers may be deposited through thin filmdeposition techniques such as ALD, CVD, and PVD. The nitride layer maybe formed from constituents such as TiN, TaN, and Zr₃N₄. The diffusionbarrier layer may prevent diffusion of elements within a chambercomponent to a surface of a substrate during the substrate processing.In some embodiments, the diffusion barrier layer may prevent diffusionof metals, such as copper, within a chamber component to a substrate'ssurface during substrate processing. The diffusion barrier layer assistsin preventing the chemical constituents of the chamber component fromcontaminating the substrate. The erosion or corrosion resistant layermay be a multi-component layer formed from constituents such as Al₂O₃,Y₂O₃, ZrO₂, YF₃, and Er₂O₃. The corrosion and/or erosion resistant layermay be deposited on the diffusion barrier layer to prevent erosion orcorrosion of the diffusion barrier layer and the underlying chambercomponent in the corrosive gas or plasma environment present in theprocess chamber. The thin film deposition techniques assist in obtainingconformal coating of substantially uniform thickness of chambercomponents having simple as well as complex geometric shapes (with holesand large aspect ratios). The multi-layer stack having a bottom thinfilm diffusion barrier layer and a top thin film erosion or corrosionresistant layer may minimize both diffusion based contamination ofprocessed wafers as well as shed particle based contamination of theprocessed wafers. The diffusion barrier layer may seal the underlyingarticle that is coated from diffusion of contaminants (for example,metal contaminant such as copper), while the erosion or corrosionresistant layer may protect both the article and the diffusion layerfrom erosion and/or corrosion by process gases and/or a plasmaenvironment.

FIG. 1 is a sectional view of a semiconductor processing chamber 100having one or more chamber components that are coated with a multi-layercoating in accordance with embodiments of the present invention. Theprocessing chamber 100 may be used for processes in which a corrosiveplasma environment having plasma processing conditions is provided. Forexample, the processing chamber 100 may be a chamber for a plasma etcheror plasma etch reactor, a plasma cleaner, and so forth. Examples ofchamber components that may include a multi-layer coating includechamber components with complex shapes and holes having large aspectratios. Some exemplary chamber components include a substrate supportassembly 148, an electrostatic chuck (ESC) 150, a ring (e.g., a processkit ring or single ring), a chamber wall, a base, a gas distributionplate, a showerhead, gas lines, a nozzle, a lid, a liner, a liner kit, ashield, a plasma screen, a flow equalizer, a cooling base, a chamberviewport, a chamber lid, and so on. The multi-layer coating, which isdescribed in greater detail below, is applied using an ALD process, aCVD process, a PVD process, or combinations thereof. ALD, CVD, and PVDwhich are described in greater detail with reference to FIGS. 2-4, allowfor the application of a conformal thin film coating of relativelyuniform thickness on all types of components including components withcomplex shapes and holes with large aspect ratios.

As illustrated, the substrate support assembly 148 has a multi-layercoating 136, in accordance with one embodiment. However, it should beunderstood that any of the other chamber components, such asshowerheads, gas lines, electrostatic chucks, nozzles and others, mayalso be coated with a multi-layer coating.

In one embodiment, the processing chamber 100 includes a chamber body102 and a showerhead 130 that enclose an interior volume 106. Theshowerhead 130 may include a showerhead base and a showerhead gasdistribution plate. Alternatively, the showerhead 130 may be replaced bya lid and a nozzle in some embodiments. The chamber body 102 may befabricated from aluminum, stainless steel or other suitable material.The chamber body 102 generally includes sidewalls 108 and a bottom 110.Any of the showerhead 130 (or lid and/or nozzle), sidewalls 108 and/orbottom 110 may include the multi-layer coating.

An outer liner 116 may be disposed adjacent the sidewalls 108 to protectthe chamber body 102. The outer liner 116 may be fabricated and/orcoated with a multi-layer coating.

An exhaust port 126 may be defined in the chamber body 102, and maycouple the interior volume 106 to a pump system 128. The pump system 128may include one or more pumps and throttle valves utilized to evacuateand regulate the pressure of the interior volume 106 of the processingchamber 100.

The showerhead 130 may be supported on the sidewall 108 of the chamberbody 102. The showerhead 130 (or lid) may be opened to allow access tothe interior volume 106 of the processing chamber 100, and may provide aseal for the processing chamber 100 while closed. A gas panel 158 may becoupled to the processing chamber 100 to provide process and/or cleaninggases to the interior volume 106 through the showerhead 130 or lid andnozzle. Showerhead 130 is used for processing chambers used fordielectric etch (etching of dielectric materials). The showerhead 130includes a gas distribution plate (GDP) 133 having multiple gas deliveryholes 132 throughout the GDP 133. The showerhead 130 may include the GDP133 bonded to an aluminum base or an anodized aluminum base. The GDP 133may be made from Si or SiC, or may be a ceramic such as Y₂O₃, Al₂O₃,YAG, and so forth.

For processing chambers used for conductor etch (etching of conductivematerials), a lid may be used rather than a showerhead. The lid mayinclude a center nozzle that fits into a center hole of the lid. The lidmay be a ceramic such as Al₂O₃, Y₂O₃, YAG, or a ceramic compoundcomprising Y₄Al₂O₉ and a solid-solution of Y₂O₃—ZrO₂. The nozzle mayalso be a ceramic, such as Y₂O₃, YAG, or the ceramic compound comprisingY₄Al₂O₉ and a solid-solution of Y₂O₃—ZrO₂. The lid, showerhead base 104,GDP 133 and/or nozzle may all be coated with a multi-layer coatingaccording to an embodiment.

Examples of processing gases that may be used to process substrates inthe processing chamber 100 include halogen-containing gases, such asC₂F₆, SF₆, SiCl₄, HBr, NF₃, CF₄, CHF₃, CH₂F₃, F, NF₃, Cl₂, CCl₄, BCl₃and SiF₄, among others, and other gases such as O₂, or N₂O. Examples ofcarrier gases include N₂, He, Ar, and other gases inert to process gases(e.g., non-reactive gases). The substrate support assembly 148 isdisposed in the interior volume 106 of the processing chamber 100 belowthe showerhead 130 or lid. The substrate support assembly 148 holds thesubstrate 144 during processing. A ring 146 (e.g., a single ring) maycover a portion of the electrostatic chuck 150, and may protect thecovered portion from exposure to plasma during processing. The ring 146may be silicon or quartz in one embodiment.

An inner liner 118 may be coated on the periphery of the substratesupport assembly 148. The inner liner 118 may be a halogen-containinggas resistant material such as those discussed with reference to theouter liner 116. In one embodiment, the inner liner 118 may befabricated from the same materials as those of outer liner 116.Additionally, the inner liner 118 may also be coated with a multi-layercoating.

In one embodiment, the substrate support assembly 148 includes amounting plate 162 supporting a pedestal 152, and an electrostatic chuck150. The electrostatic chuck 150 further includes a thermally conductivebase 164 and an electrostatic puck 166 bonded to the thermallyconductive base by a bond 138, which may be a silicone bond in oneembodiment. An upper surface of the electrostatic puck 166 may becovered by the multi-layer coating 136 in the illustrated embodiment.The multi-layer coating 136 may be disposed on the entire exposedsurface of the electrostatic chuck 150 including the outer and sideperiphery of the thermally conductive base 164 and the electrostaticpuck 166 as well as any other geometrically complex parts or holeshaving large aspect ratios in the electrostatic chuck. The mountingplate 162 is coupled to the bottom 110 of the chamber body 102 andincludes passages for routing utilities (e.g., fluids, power lines,sensor leads, etc.) to the thermally conductive base 164 and theelectrostatic puck 166.

The thermally conductive base 164 and/or electrostatic puck 166 mayinclude one or more optional embedded heating elements 176, embeddedthermal isolators 174 and/or conduits 168, 170 to control a lateraltemperature profile of the substrate support assembly 148. The conduits168, 170 may be fluidly coupled to a fluid source 172 that circulates atemperature regulating fluid through the conduits 168, 170. The embeddedisolator 174 may be disposed between the conduits 168, 170 in oneembodiment. The heater 176 is regulated by a heater power source 178.The conduits 168, 170 and heater 176 may be utilized to control thetemperature of the thermally conductive base 164. The conduits andheater heat and/or cool the electrostatic puck 166 and a substrate(e.g., a wafer) 144 being processed. The temperature of theelectrostatic puck 166 and the thermally conductive base 164 may bemonitored using a plurality of temperature sensors 190, 192, which maybe monitored using a controller 195.

The electrostatic puck 166 may further include multiple gas passagessuch as grooves, mesas and other surface features that may be formed inan upper surface of the puck 166. These surface features may all becoated with a multi-layer coating according to an embodiment. The gaspassages may be fluidly coupled to a source of a heat transfer (orbackside) gas such as He via holes drilled in the puck 166. Inoperation, the backside gas may be provided at controlled pressure intothe gas passages to enhance the heat transfer between the electrostaticpuck 166 and the substrate 144.

The electrostatic puck 166 includes at least one clamping electrode 180controlled by a chucking power source 182. The electrode 180 (or otherelectrode disposed in the puck 166 or base 164) may further be coupledto one or more RF power sources 184, 186 through a matching circuit 188for maintaining a plasma formed from process and/or other gases withinthe processing chamber 100. The sources 184, 186 are generally capableof producing RF signal having a frequency from about 50 kHz to about 3GHz and a power of up to about 10,000 Watts.

FIG. 2 depicts a deposition process in accordance with a variety of ALDtechniques. Various types of ALD processes exist and the specific typemay be selected based on several factors such as the surface to becoated, the coating material, chemical interaction between the surfaceand the coating material, etc. The general principle of an ALD processcomprises growing or depositing a thin film layer by repeatedly exposingthe surface to be coated to sequential alternating pulses of gaseouschemical precursors that chemically react with the surface one at a timein a self-limiting manner.

FIG. 2 illustrates an article 210 having a surface 205. Each individualchemical reaction between a precursor and the surface is known as a“half-reaction.” During each half reaction, a precursor is pulsed ontothe surface for a period of time sufficient to allow the precursor tofully react with the surface. The reaction is self-limiting as theprecursor will react with a finite number of available reactive sites onthe surface, forming a uniform continuous adsorption layer on thesurface. Any sites that have already reacted with a precursor willbecome unavailable for further reaction with the same precursor unlessand/or until the reacted sites are subjected to a treatment that willform new reactive sites on the uniform continuous coating. Exemplarytreatments may be plasma treatment, treatment by exposing the uniformcontinuous adsorption layer to radicals, or introduction of a differentprecursor able to react with the most recent uniform continuous filmlayer adsorbed to the surface.

In FIG. 2, article 210 having surface 205 may be introduced to a firstprecursor 260 for a first duration until a first half reaction of thefirst precursor 260 with surface 205 partially forms film layer 215 byforming an adsorption layer 214. Subsequently, article 210 may beintroduced to a second precursor 265 (also referred to as a reactant)that reacts with the adsorption layer 214 to fully form the layer 215.The first precursor 260 may be a precursor for yttrium or another metal,for example. The second precursor 265 may be an oxygen precursor if thelayer 215 is an oxide, a fluorine precursor if the layer 215 is afluoride, or a nitrogen precursor if this layer is a nitride. Thearticle 210 may alternately be exposed to the first precursor 260 andsecond precursor 265 up to n number of times to achieve a targetthickness for the layer 215. N may be an integer from 1 to 100, forexample. Film layer 215 may be uniform, continuous and conformal. Thefilm layer 215 may also have a very low porosity of less than 1% inembodiments, less than 0.1% in some embodiments, or approximately 0% infurther embodiments. Subsequently, article 210 having surface 205 andfilm layer 215 may be introduced to a third precursor 270 that reactswith layer 215 to partially form a second film layer 220 by forming asecond adsorption layer 218. Subsequently, article 210 may be introducedto another precursor 275 (also referred to as a reactant) that reactswith adsorption layer 218 leading to a second half reaction to fullyform the layer 220. The article 210 may alternately be exposed to thethird precursor 270 and fourth precursor 275 up to m number of times toachieve a target thickness for the layer 220. M may be an integer from 1to 100, for example. The second film layer 220 may be uniform,continuous and conformal. The second film layer 220 may also have a verylow porosity of less than 1% in some embodiments, less than 0.1% in someembodiments, or approximately 0% in further embodiments. Thereafter, thesequence of introducing the article 210 to precursors 260 and 265 nnumber of times and then to precursors 270 and 275 m number of times maybe repeated and performed x number of times. X may be an integer from 1to 100, for example. A result of the sequence may be to grow additionallayers 225, 230, 235, and 245. The number and thickness of the variouslayers may be independently selected based on the targeted coatingthickness and properties. The various layers may remain intact (i.e.separate) or in some embodiments may be interdiffused.

The surface reactions (e.g., half-reactions) are done sequentially.Prior to introduction of a new precursor, the chamber in which the ALDprocess takes place may be purged with an inert carrier gas (such asnitrogen or air) to remove any unreacted precursors and/orsurface-precursor reaction byproducts. At least two precursors are used.In some embodiments, more than two precursors may be used to grow filmlayers having the same composition (e.g., to grow multiple layers ofY₂O₃ on top of each other). In other embodiments, different precursorsmay be used to grow different film layers having different compositions.

ALD processes may be conducted at various temperatures. The optimaltemperature range for a particular ALD process is referred to as the“ALD temperature window.” Temperatures below the ALD temperature windowmay result in poor growth rates and non-ALD type deposition.Temperatures above the ALD temperature window may result in thermaldecomposition of the article or rapid desorption of the precursor. TheALD temperature window may range from about 200° C. to about 400° C. Insome embodiments, the ALD temperature window is between about 150° C. toabout 350° C.

The ALD process allows for conformal film layers having uniform filmthickness on articles and surfaces having complex geometric shapes,holes with large aspect ratios, and three-dimensional structures.Sufficient exposure time of the precursors to the surface enables theprecursors to disperse and fully react with the surface in its entirety,including all of its three-dimensional complex features. The exposuretime utilized to obtain conformal ALD in high aspect ratio structures isproportionate to the square of the aspect ratio and can be predictedusing modeling techniques. Additionally, the ALD technique isadvantageous over other commonly used coating techniques because itallows in-situ on demand material synthesis of a particular compositionor formulation without the need for a lengthy and difficult fabricationof source materials (such as powder feedstock and sintered targets). Afirst set of layers 215, 220, 225, and 230 may together form a diffusionbarrier layer selected from a group consisting of TiN_(x), TaN_(x),Zr₃N₄, and TiZr_(x)N_(y) in some embodiments. The diffusion barrierlayers may be deposited from one pair of ALD precursors or fromalternating pairs of ALD precursors used for forming, for example, a TiNfilm, TaN film, and a Zr₃N₄ film. In some embodiments, the films formedfrom alternating precursors may remain as intact layers. In otherembodiments, the films formed from alternating precursors may beannealed to form an interdiffused diffusion barrier layer. In someembodiments, each of the layers 215, 220, 225, and 230 is a nanolayer ofthe same material (e.g., of TiN_(x), TaN or Zr₃N₄) that together forms asingle thicker diffusion barrier layer.

In some embodiments, a second set of layers 235 and 245 may togetherform an erosion resistant layer selected from a group consisting of YF₃,Y₂O₃, Er₂O₃, Al₂O₃, ZrO₂, ErAl_(x)O_(y), YO_(x)F_(y), YAl_(x)O_(y),YZr_(x)O_(y) and YZr_(x)Al_(y)O_(z). The erosion resistant layer may bedeposited from one pair of ALD precursors or from alternating pairs ofALD precursors used for forming, for example, an Al₂O₃ film, Y₂O₃ film,ZrO₂ film, YF₃ film, and/or an Er₂O₃ film. In some embodiments, thefilms formed from alternating precursors may remain as intact layers. Inother embodiments, the films formed from alternating precursors may beannealed to form an interdiffused erosion resistant layer. In someembodiments, each of the layers 235 and 245 is a nanolayer of the samematerial (e.g., of Al₂O₃, Y₂O₃, ZrO₂, YF₃, or Er₂O₃) that together formsa single thicker erosion resistant layer.

In some embodiments, the multi-layer coating may be deposited on asurface of an article via CVD. An exemplary CVD system is illustrated inFIG. 3. The system comprises a chemical vapor precursor supply system305 and a CVD reactor 310. The role of the vapor precursor supply system305 is to generate vapor precursors 320 from a starting material 315,which could be in a solid, liquid, or gas form. The vapors are thentransported into CVD reactor 310 and get deposited as thin film 325 onarticle 330 which is positioned on article holder 335.

CVD reactor 310 heats article 330 to a deposition temperature usingheater 340. In some embodiments, the heater may heat the CVD reactor'swall (also known as “hot-wall reactor”) and the reactor's wall maytransfer heat to the article. In other embodiments, the article alonemay be heated while maintaining the CVD reactor's wall cold (also knownas “cold-wall reactor”). It is to be understood that the CVD systemconfiguration should not be construed as limiting. A variety ofequipment could be utilized for a CVD system and the equipment is chosento obtain optimum processing conditions that may give a coating withuniform thickness, surface morphology, structure, and composition.

The various CVD processes comprise of the following process: (1)generate active gaseous reactant species (also known as “precursors”)from the starting material; (2) transport the precursors into thereaction chamber (also referred to as “reactor”); (3) absorb theprecursors onto the heated article; (4) participate in a chemicalreaction between the precursor and the article at the gas-solidinterface to form a deposit and a gaseous by-product; and (5) remove thegaseous by-product and unreacted gaseous precursors from the reactionchamber.

Suitable CVD precursors may be stable at room temperature, may have lowvaporization temperature, can generate vapor that is stable at lowtemperature, have suitable deposition rate (low deposition rate for thinfilm coatings and high deposition rate for thick film coatings),relatively low toxicity, be cost effective, and relatively pure. Forsome CVD reactions, such as thermal decomposition reaction (also knownas “pyrolysis”) or a disproportionation reaction, a chemical precursoralone may suffice to complete the deposition. For other CVD reactions,other agents (listed in Table 1 below) in addition to a chemicalprecursor may be utilized to complete the deposition.

TABLE 1 Chemical Precursors and Additional Agents Utilized in VariousCVD Reactions CVD reaction Chemical Precursor Additional Agents ThermalDecomposition Halides N/A (Pyrolysis) Hydrides Metal carbonylMetalorganic Reduction Halides Reducing agent Oxidation HalidesOxidizing agent Hydrides Metalorganic Hydrolysis Halides Hydrolyzingagent Nitridation Halides Nitriding agent Hydrides HalohydridesDisproportionation Halides N/A

CVD has many advantages including its capability to deposit highly denseand pure coatings and its ability to produce uniform films with goodreproducibility and adhesion at reasonably high deposition rates. Layersdeposited using CVD in embodiments may have a porosity of below 1%, anda porosity of below 0.1% (e.g., around 0%). Therefore, it can be used touniformly coat complex shaped components and deposit conformal filmswith good conformal coverage (e.g., with substantially uniformthickness). CVD may also be utilized to deposit a film made of aplurality of components, for example, by feeding a plurality of chemicalprecursors at a predetermined ratio into a mixing chamber and thensupplying the mixture to the CVD reactor system.

The CVD reactor 310 may be used to form a diffusion barrier layer and/oran erosion resistant layer that is resistant to erosion and/or corrosionby plasma environments in embodiments. Layer 325 may form a diffusionbarrier layer selected from a group consisting of TiN_(x), TaN_(x),Zr₃N₄, and TiZr_(x)N_(y) in embodiments. Layer 345 covering diffusionbarrier layer 325 may be an erosion resistant layer selected from agroup consisting of YF₃, Y₂O₃, Er₂O₃, Al₂O₃, ZrO₂, ErAl_(x)O_(y),YO_(x)F_(y), YAl_(x)O_(y), YZr_(x)O_(y) and YZr_(x)Al_(y)O_(z), in someembodiments.

In some embodiments, the multi-layer coating may be deposited on asurface of an article via PVD. PVD processes may be used to deposit thinfilms with thicknesses ranging from a few nanometers to severalmicrometers. The various PVD processes share three fundamental featuresin common: (1) evaporating the material from a solid source with theassistance of high temperature or gaseous plasma; (2) transporting thevaporized material in vacuum to the article's surface; and (3)condensing the vaporized material onto the article to generate a thinfilm layer. An illustrative PVD reactor is depicted in FIG. 4 anddiscussed in more detail below.

FIG. 4 depicts a deposition mechanism applicable to a variety of PVDtechniques and reactors. PVD reactor chamber 400 may comprise a plate410 adjacent to the article 420 and a plate 415 adjacent to the target430. Air may be removed from reactor chamber 400, creating a vacuum.Then argon gas may be introduced into the reactor chamber, voltage maybe applied to the plates, and a plasma comprising electrons and positiveargon ions 440 may be generated. Positive argon ions 440 may beattracted to negative plate 415 where they may hit target 430 andrelease atoms 435 from the target. Released atoms 435 may gettransported and deposited as a thin film 425 onto article 420.

The PVD reactor chamber 400 may be used to form a diffusion barrierlayer and/or an erosion resistant layer in embodiments. Layer 425 mayform a diffusion barrier layer selected from a group consisting ofTiN_(x), TaN_(x), Zr₃N₄, and TiZr_(x)N_(y) in embodiments. Layer 445covering diffusion barrier layer 425 may be an erosion resistant layerselected from a group consisting of YF₃, Y₂O₃, Er₂O₃, Al₂O₃, ZrO₂,ErAl_(x)O_(y), YO_(x)F_(y), YAl_(x)O_(y), YZr_(x)O_(y) andYZr_(x)Al_(y)O_(z), in some embodiments.

Article 210 in FIG. 2, article 330 in FIG. 3, and article 420 in FIG. 4may represent various semiconductor process chamber components includingbut not limited to substrate support assembly, an electrostatic chuck(ESC), a ring (e.g., a process kit ring or single ring), a chamber wall,a base, a gas distribution plate, gas lines, a showerhead, a nozzle, alid, a liner, a liner kit, a shield, a plasma screen, a flow equalizer,a cooling base, a chamber viewport, a chamber lid, and so on. Thearticles and their surfaces may be made from a metal (such as aluminum,stainless steel), a ceramic, a metal-ceramic composite, a polymer, apolymer ceramic composite, or other suitable materials, and may furthercomprise materials such as AlN, Si, SiC, Al₂O₃, SiO₂, and so on.

With the ALD, CVD, and PVD techniques, diffusion barrier films, such asTiN_(x), TaN_(x), Zr₃N₄, and TiZr_(x)N_(y), and erosion resistant films,such as YF₃, Y₂O₃, Er₂O₃, Al₂O₃, ZrO₂, ErAl_(x)O_(y), YO_(x)F_(y),YAl_(x)O_(y), YZr_(x)O_(y) and YZr_(x)Al_(y)O_(z) can be formed. In someembodiments, the diffusion barrier layer and the erosion resistant layermay both be deposited using the same technique, i.e. both may depositedvia ALD, both may be deposited via CVD, or both may be deposited viaPVD. In other embodiments, the diffusion barrier layer may be depositedby one technique and the erosion resistant layer may be deposited byanother technique. If both layers are deposited via ALD, for example,the diffusion barrier layer may be adsorbed and deposited by propersequencing of the precursors used to adsorb and deposit TiN, TaN, andZr₃N₄, and the erosion resistant films may be adsorbed and deposited byproper sequencing of the precursors used to adsorb and deposit Y₂O₃,Al₂O₃, YF₃, ZrO₂, and Er₂O₃, as discussed in more detail below.

FIG. 5 illustrates a method 500 for forming a multi-layer coating on anarticle according to an embodiment. The method may optionally begin byselecting a composition for the multi-layer coating (not illustrated inFIG. 5). The composition selection and method of forming may beperformed by the same entity or by multiple entities. Pursuant to block505, the method comprises depositing a diffusion barrier layer onto asurface of an article using a first deposition process selected from agroup consisting of ALD, CVD, and PVD. The diffusion barrier layer maycomprise a plurality of intact layers. The plurality of intact layersmay be made out of a plurality of precursors, forming a diffusionbarrier layer. The diffusion barrier layer may have a thickness rangingfrom about 10 nm to about 100 nm and may be selected from a groupconsisting of TiN_(x), TaN_(x), Zr₃N₄, and TiZr_(x)N_(y).

Pursuant to block 510, the method optionally further comprise annealingthe diffusion barrier layer. In some embodiments, the annealing mayresult in a diffusion barrier layer comprising an interdiffused solidstate phase of the plurality of components present in the plurality ofintact layers. Annealing may be performed at a temperature ranging fromabout 800° C. to about 1800° C., from about 800° C. to about 1500° C.,or from about 800° C. to about 1000° C. The annealing temperature may beselected based on the material of construction of the article, surface,and film layers so as to maintain their integrity and refrain fromdeforming, decomposing, or melting any or all of these components.

Pursuant to block 515, the method further comprises depositing anerosion resistant layer onto the diffusion barrier layer using a seconddeposition process selected from a group consisting of ALD, CVD, andPVD. The erosion resistant layer may comprise a plurality of intactlayers. The plurality of intact layers may be made out of a plurality ofprecursors, forming an erosion resistant layer. The erosion resistantlayer may have a thickness of up to about 1 micrometer, e.g. from about20 nm to about 1 micrometer, and may be selected from a group consistingof YF₃, Y₂O₃, Er₂O₃, Al₂O₃, ZrO₂, ErAl_(x)O_(y), YO_(x)F_(y),YAl_(x)O_(y), YZr_(x)O_(y) and YZr_(x)Al_(y)O_(z).

In some embodiments, the method may optionally further compriseannealing the erosion resistant layer, pursuant to block 520. In someembodiments, the annealing may result in an erosion resistant layercomprising an interdiffused solid state phase of the plurality ofcomponents present in the plurality of intact layers. The annealingtemperature may be similar to the annealing temperature of the diffusionbarrier layer listed above.

In some embodiments, the barrier layer and the erosion resistant layermay both be annealed and interdiffused (FIG. 6D). In some embodiments, asingle annealing process is performed after deposition of the erosionresistant layer to anneal and interdiffuse nanolayers of the diffusionbarrier layer and nanolayers of the erosion resistant layer. In someembodiments, one of the barrier layer and the erosion resistant layerare annealed and interdiffused, while the other layer is not annealed.(See FIG. 6B and FIG. 6C). In other embodiments, neither of the barrierlayer or the erosion resistant layer is annealed or interdiffused (FIG.6A). The various embodiments are illustrated in FIGS. 6A-6D anddiscussed in further detail below.

In some embodiments, the first deposition process of the diffusionbarrier layer and the second deposition process of the erosion resistantlayer may be identical, for example, both processes may be ALD, bothprocess may be CVD, or both processes may be PVD. In other embodiments,the first deposition process of the diffusion barrier layer and thesecond deposition process of the erosion resistant layer may vary.Regardless of the deposition method, the final multi-layer coating maybe able to withstand temperature cycling from about 20° C. to about 450°C. without cracking.

When the first or second deposition processes are ALD or CVD, a properprecursor or a plurality of precursors may be selected to ultimatelyform the diffusion barrier layer(s), erosion resistant layer(s), andmulti-layer coating.

For instance, a TiN_(x) diffusion barrier layer may be deposited via ALDor CVD from at least one Ti-containing precursor selected from the groupconsisting of bis(diethylamido)bis(dimethylamido)titanium(IV),tetrakis(diethylamido)titanium(IV), tetrakis(dimethylamido)titanium(IV),tetrakis(ethylmethylamido)titanium(IV), titanium(IV) bromide,titanium(IV) chloride, and titanium(IV) tert-butoxide.

A TaN_(x) diffusion barrier layer may be deposited via ALD or CVD fromat least one Ta precursor selected from the group consisting ofpentakis(dimethylamido)tantalum(V), tantalum(V) chloride, tantalum(V)ethoxide, and tris(diethylamino)(tert-butylimido)tantalum(V).

A TiZr_(x)N_(y) diffusion barrier layer may be deposited via ALD or CVDfrom at least one Ti precursor and from at least one Zr precursor. Tiprecursors may be selected from the group consisting ofbis(diethylamido)bis(dimethylamido)titanium(IV),tetrakis(diethylamido)titanium(IV), tetrakis(dimethylamido)titanium(IV),tetrakis(ethylmethylamido)titanium(IV), titanium(IV) bromide,titanium(IV) chloride, and titanium(IV) tert-butoxide. Zr precursors maybe selected from the group consisting of zirconium (IV) bromide,zirconium (IV) chloride, zirconium (IV) tert-butoxide,tetrakis(diethylamido)zirconium (IV), tetrakis(dimethylamido)zirconium(IV), and tetrakis(ethylmethylamido)zirconium (IV). In some embodiments,the stoichiometric ratios of the various components may form aTi_(0.2)Zr_(0.2)N_(0.6) diffusion barrier layer.

A Zr₃N₄ diffusion barrier layer may be deposited via ALD or CVD from atleast one Zr precursor selected from the group consisting of zirconium(IV) bromide, zirconium (IV) chloride, zirconium (IV) tert-butoxide,tetrakis(diethylamido)zirconium (IV), tetrakis(dimethylamido)zirconium(IV), and tetrakis(ethylmethylamido)zirconium (IV).

A ErAl_(x)O_(y) erosion resistant layer may be deposited via ALD or CVDfrom at least one Er precursor and from at least one Al precursor. Erprecursors may be selected from a group consisting oftris-methylcyclopentadienyl erbium (III) (Er(MeCp)₃), erbium boranamide(Er(BA)₃), Er(TMHD)₃, erbium(III)tris(2,2,6,6-tetramethyl-3,5-heptanedionate), andtris(butylcyclopentadienyl)erbium(III). Al precursors may be selectedfrom the group consisting of diethylaluminum ethoxide,tris(ethylmethylamido)aluminum, aluminum sec-butoxide, aluminumtribromide, aluminum trichloride, triethylaluminum, triisobutylaluminum,trimethylaluminum, and tris(diethylamido)aluminum.

A YAl_(x)O_(y) erosion resistant layer may be deposited via ALD or CVDfrom at least one Y precursor and from at least one Al precursor. Yprecursors may be selected from the group consisting oftris(N,N-bis(trimethylsilyl)amide)yttrium (III), yttrium (III)butoxide,tris(cyclopentadienyl)yttrium(III), and Y(thd)3(thd=2,2,6,6-tetramethyl-3,5-heptanedionato).

A YO_(x)F_(y) erosion resistant layer may be deposited via ALD or CVDfrom at least one Y precursor selected from the group consisting oftris(N,N-bis(trimethylsilyl)amide)yttrium (III), yttrium (III)butoxide,tris(cyclopentadienyl)yttrium(III), and Y(thd)3(thd=2,2,6,6-tetramethyl-3,5-heptanedionato).

A YZr_(x)O_(y) erosion resistant layer may be deposited via ALD or CVDfrom at least one Y precursor and from at least one Zr precursor. Zrprecursors may be selected from the group consisting of zirconium (IV)bromide, zirconium (IV) chloride, zirconium (IV) tert-butoxide,tetrakis(diethylamido)zirconium (IV), tetrakis(dimethylamido)zirconium(IV), and tetrakis(ethylmethylamido)zirconium (IV).

A YZr_(x)Al_(y)O_(z) erosion resistant layer may be deposited via ALD orCVD from at least one Y precursor, from at least one Zr precursor andfrom at least one Al precursor.

An Er₂O₃ erosion resistant layer may be deposited via ALD or CVD from atleast one Er precursor selected from a group consisting oftris-methylcyclopentadienyl erbium (III) (Er(MeCp)₃), erbium boranamide(Er(BA)₃), Er(TMHD)₃, erbium(III)tris(2,2,6,6-tetramethyl-3,5-heptanedionate), andtris(butylcyclopentadienyl)erbium(III).

An Al₂O₃ erosion resistant layer may be deposited via ALD or CVD from atleast one Al precursor selected from the group consisting ofdiethylaluminum ethoxide, tris(ethylmethylamido)aluminum, aluminumsec-butoxide, aluminum tribromide, aluminum trichloride,triethylaluminum, triisobutylaluminum, trimethylaluminum, andtris(diethylamido)aluminum.

A Y₂O₃ erosion resistant layer may be deposited via ALD or CVD from atleast one Y precursor selected from the group consisting oftris(N,N-bis(trimethylsilyl)amide)yttrium (III), yttrium (III)butoxide,tris(cyclopentadienyl)yttrium(III), and Y(thd)3(thd=2,2,6,6-tetramethyl-3,5-heptanedionato).

A YF₃ erosion resistant layer may be deposited via ALD or CVD from atleast one Y precursor.

A ZrO₂ erosion resistant layer may be deposited via ALD or CVD from atleast one Zr precursor selected from the group consisting of zirconium(IV) bromide, zirconium (IV) chloride, zirconium (IV) tert-butoxide,tetrakis(diethylamido)zirconium (IV), tetrakis(dimethylamido)zirconium(IV), and tetrakis(ethylmethylamido)zirconium (IV).

In some embodiments, precursor gases providing an oxygen source, such asozone, water vapor, and oxygen radicals from plasma may be used inconjunction with any of the precursors listed herein above. In someembodiments, precursor gases providing a nitrogen source, such asammonia, nitrogen, and radicals from nitrogen plasma may be used inconjunction with any of the precursors listed herein above. In someembodiments, precursor gases providing a fluorine source, such asfluorine, HF, and fluorine radicals from a fluorine plasma may be usedin conjunction with any of the precursors listed herein above. It is tobe understood that the precursors listed herein above are merelyillustrative and should not be construed as limiting.

FIGS. 6A-6D depict variations of a multi-layer coating according todifferent embodiments. FIG. 6A illustrates a multi-layer coating for anarticle 610 having a surface 605. For example, article 610 may includevarious semiconductor process chamber components including but notlimited to substrate support assembly, an electrostatic chuck (ESC), aring (e.g., a process kit ring or single ring), a chamber wall, a base,a gas distribution plate, gas lines, a showerhead, a nozzle, a lid, aliner, a liner kit, a shield, a plasma screen, a flow equalizer, acooling base, a chamber viewport, a chamber lid, and so on. Thesemiconductor process chamber component may be made from a metal (suchas aluminum, stainless steel), a ceramic, a metal-ceramic composite, apolymer, a polymer ceramic composite, or other suitable materials, andmay further comprise materials such as AlN, Si, SiC, Al₂O₃, SiO₂, and soon.

In FIGS. 6A-6D, the multi-layer coating deposited on surface 605comprises a diffusion barrier layer 615 or 645 selected from a groupconsisting of TiN_(x), TaN_(x), Zr₃N₄, and TiZr_(x)N_(y) and an erosionresistant layer 625 or 635 selected from a group consisting of YF₃,Y₂O₃, Er₂O₃, Al₂O₃, ZrO₂, ErAl_(x)O_(y), YO_(x)F_(y), YAl_(x)O_(y),YZr_(x)O_(y) and YZr_(x)Al_(y)O_(z). The erosion resistant layer coversthe diffusion barrier layer.

In FIG. 6A, both diffusion barrier layer 615 and erosion resistant layer625 comprise a plurality of intact layers 650 and 630, respectively. InFIG. 6B, diffusion barrier layer 615 comprises a plurality of intactlayers 650, whereas erosion resistant layer 635 may be in aninterdiffused solid state phase of the plurality of components composingthe erosion resistant layer. In FIG. 6C, diffusion barrier layer 645 maybe in an interdiffused solid state phase of the plurality of componentscomposing the diffusion barrier layer, whereas erosion resistant layer625 may comprise a plurality of intact layers. In FIG. 6D, bothdiffusion barrier layer 645 and erosion resistant layer 635 may be in aninter-diffused solid state phase of the plurality of componentscomposing each of the layers. Alternatively, the components of thediffusion barrier layer 645 may interdiffuse to form multiple differentphases and/or the components of the erosion resistant layer 635 mayinterdiffuse to form multiple different phases.

Although the diffusion barrier layer and the erosion resistant layerillustrated in FIGS. 6A-6D may seem as having a similar thickness, thesefigures should not be construed as limiting. In some embodiments, thediffusion barrier layer may have a lesser thickness than the erosionresistant layer. In some embodiments, the diffusion barrier layer mayhave a greater thickness than the erosion resistant layer. In someembodiments, the thickness of the diffusion barrier layer and of theerosion resistant layer may be the same. The diffusion barrier layer mayhave a thickness ranging from about 10 nm to about 100 nm. The erosionresistant layer may have a thickness of up to about 1 micrometer, e.g.,from about 20 nm to about 1 micrometer.

The surface roughness of the multi-layer coating may be similar to theroughness of the semiconductor process chamber component. In someembodiments, the surface roughness of the multi-layer coating may rangefrom about 20 to about 45 microinches.

An aluminum oxide erosion resistant layer deposited by ALD may have thefollowing properties: a breakdown voltage of about 360 volts at athickness of about 1 micrometer, a scratch adhesion failure force basedon a 10 micron diamond stylus scratch adhesion test of about 140 mN at athickness of about 1 micrometer, a Vickers hardness of about 12.9-13.5GPa, and a time to failure of about 1-28 hours for a one micron thickfilm based on a bubble test. A yttrium oxide erosion resistant layerdeposited by ALD may have the following properties: a breakdown voltageof about 475 volts at a thickness of about 1 micrometer, a scratchadhesion failure force based on a 10 micrometer diamond stylus scratchadhesion test of 34 mN at a thickness of about 100 nm, a Vickershardness of about 11.5 GPa to about 12.9 GPa, and about 14 minutes timeto failure for a one micrometer film based on a bubble test.

The preceding description sets forth numerous specific details such asexamples of specific systems, components, methods, and so forth, inorder to provide a good understanding of several embodiments of thepresent invention. It will be apparent to one skilled in the art,however, that at least some embodiments of the present invention may bepracticed without these specific details. In other instances, well-knowncomponents or methods are not described in detail or are presented insimple block diagram format in order to avoid unnecessarily obscuringthe present invention. Thus, the specific details set forth are merelyexemplary. Particular implementations may vary from these exemplarydetails and still be contemplated to be within the scope of the presentinvention.

Reference throughout this specification to “one embodiment” or “anembodiment” means that a particular feature, structure, orcharacteristic described in connection with the embodiment is includedin at least one embodiment. Thus, the appearances of the phrase “in oneembodiment” or “in an embodiment” in various places throughout thisspecification are not necessarily all referring to the same embodiment.In addition, the term “or” is intended to mean an inclusive “or” ratherthan an exclusive “or.” When the term “about” or “approximately” is usedherein, this is intended to mean that the nominal value presented isprecise within ±10%.

When the term “porosity” is used herein, it is intended to describe theamount of empty space within the coating. For example, a 5% porositywould mean that 5% of the total volume of the coating is actually emptyspace.

When the term “surface roughness” is used herein, it described a measureof the roughness of a surface using a profilometer (a needle draggedacross the surface).

When the term “break down voltage” or “BDV” is used herein, it refers toevaluation of the coating using voltage. The BDV value is the voltagereached when the coating destructively arcs.

When the term “adhesion” is used herein, it refers to the strength ofthe coating to adhere to an underlying article or underlying coating.

When the term “hardness” is used herein, it refers to the amount ofcompression that a film can withstand without damage.

When the term “bubble test” is used herein, it refers to a test in whichthe coated article is placed in hydrochloric acid solution, and the timeuntil the formation of a bubble on the liquid is measured. The formationof the bubble indicates that the article itself has reacted and thecoating has been penetrated.

The ability to withstand the temperature cycling means that themulti-layer coating can be processed through temperature cycles withoutexperiencing cracking.

Although the operations of the methods herein are shown and described ina particular order, the order of the operations of each method may bealtered so that certain operations may be performed in an inverse orderor so that certain operation may be performed, at least in part,concurrently with other operations. In another embodiment, instructionsor sub-operations of distinct operations may be in an intermittentand/or alternating manner.

It is to be understood that the above description is intended to beillustrative, and not restrictive. Many other embodiments will beapparent to those of skill in the art upon reading and understanding theabove description. The scope of the disclosure should, therefore, bedetermined with reference to the appended claims, along with the fullscope of equivalents to which such claims are entitled.

What is claimed is:
 1. A coated article comprising an article and amulti-layer coating deposited on a surface of the article, themulti-layer coating comprising: a diffusion barrier layer selected froma group consisting of TiN_(x), TaN_(x), Zr₃N₄, and TiZr_(x)N_(y),wherein the diffusion barrier layer seals the article from diffusion ofmetal contaminants therethrough; and an erosion resistant layercomprising YZr_(x)O_(y), wherein the erosion resistant layer contactsand covers the diffusion barrier layer.
 2. The coated article of claim1, wherein the diffusion barrier layer has a thickness ranging fromabout 10 nm to about 100 nm, and wherein the erosion resistant layer hasa thickness of up to about 1 micrometer.
 3. The coated article of claim1, wherein the multi-layer coating is able to withstand temperaturecycling from about 20° C. to about 450° C. without cracking.
 4. Thecoated article of claim 1, wherein the diffusion barrier layer isconformal to the surface of the article.
 5. The coated article of claim1, wherein the diffusion barrier layer has a porosity of less than 1%.6. The coated article of claim 1, wherein the diffusion barrier layerhas a porosity of less than 0.1%.
 7. The coated article of claim 1,wherein the erosion resistant layer is conformal to the diffusionbarrier layer.
 8. The coated article of claim 1, wherein the erosionresistant layer has a porosity of less than 1%.
 9. The coated article ofclaim 1, wherein the erosion resistant layer has a porosity of less than0.1%.
 10. A coated process chamber component comprising: a processchamber component having a surface; and a multi-layer coating on thesurface, comprising: a diffusion barrier layer selected from a groupconsisting of TiN_(x), TaN_(x), Zr₃N₄, and TiZr_(x)N_(y), wherein thediffusion barrier layer seals the surface from diffusion of metalcontaminants there through; and an erosion resistant layer comprisingYZr_(x)O_(y), wherein the erosion resistant layer contacts and coversthe diffusion barrier layer.
 11. The coated process chamber component ofclaim 10, wherein the diffusion barrier layer has a thickness rangingfrom about 10 nm to about 100 nm, and wherein the erosion resistantlayer has a thickness of up to about 1 micrometer.
 12. The coatedprocess chamber component of claim 10, wherein the diffusion barrierlayer is conformal to the surface of the process chamber component. 13.The coated process chamber component of claim 10, wherein the diffusionbarrier layer has a porosity of less than 1%.
 14. The coated processchamber component of claim 10, wherein the diffusion barrier layer has aporosity of less than 0.1%.
 15. The coated process chamber component ofclaim 10, wherein the erosion resistant layer is conformal to thediffusion barrier layer.
 16. The coated process chamber component ofclaim 10, wherein the erosion resistant layer has a porosity of lessthan 1%.
 17. The coated process chamber component of claim 10, whereinthe erosion resistant layer has a porosity of less than 0.1%.